目前接触比较多的就是通过dialer应用来启动/触发暗码。
也有通过Calculator来实现的。
本文以Dialer为例，
1.经过调试定位，发现拨号盘接对应的Activity为DialtactsActivity。
2.DialtactsActivity中有个showDialpadFragment方法，用来加载显示拨号盘，因为有可能此时拨号盘正处于收缩/隐藏状态。
/** * Initiates a fragment transaction to show the dialpad fragment. Animations and other visual * updates are handled by a callback which is invoked after the dialpad fragment is shown. * @see #onDialpadShown */ private void showDialpadFragment(boolean animate) { if (mIsDialpadShown || mStateSaved) { return; } mIsDialpadShown = true; mListsFragment.setUserVisibleHint(false); final FragmentTransaction ft = getFragmentManager().beginTransaction(); if (mDialpadFragment == null) { mDialpadFragment = new DialpadFragment(); ft.add(R.id.dialtacts_container, mDialpadFragment, TAG_DIALPAD_FRAGMENT); } else { ft.show(mDialpadFragment); } //mDialpadFragment.setAnimate(animate); AnalyticsUtil.sendScreenView(mDialpadFragment); ft.commit(); maybeEnterSearchUi(); if (animate) { mFloatingActionButtonController.scaleOut(); } else { mFloatingActionButtonController.setVisible(false); } mActionBarController.onDialpadUp(); mListsFragment.getView().animate().alpha(0).withLayer(); } 3.接下来重点处理实现就在DialpapFragment中，首先来看类的声明/继承。 import com.android.dialer.dialpad.DialpadFragment; /** * Fragment that displays a twelve-key phone dialpad. */ public class DialpadFragment extends Fragment implements View.OnClickListener, View.OnLongClickListener, View.OnKeyListener, AdapterView.OnItemClickListener, TextWatcher, PopupMenu.OnMenuItemClickListener, DialpadKeyButton.OnPressedListener, /// M: add for plug-in @{ DialpadExtensionAction {从以上类实现/继承中可以发现，其继承了TextWatcher类，也正是这个类使之能够监听实现输入变化。
TextWatcher有3个重要方法，分别为：beforeTextChanged，onTextChanged和afterTextChanged。分别看下面那份源码。
onTextChanged
其中最重点的是afterTextChanged方法，其调用了SpecialCharSequenceMgr辅助工具类的handleChars方法。
4.handleChars方法中，会对各种特殊的secret code进行匹配处理。
public static boolean handleChars(Context context, String input, EditText textField) { //get rid of the separators so that the string gets parsed correctly String dialString = PhoneNumberUtils.stripSeparators(input); if (handleDeviceIdDisplay(context, dialString) //*#06# || handleRegulatoryInfoDisplay(context, dialString) || handlePinEntry(context, dialString) || handleAdnEntry(context, dialString, textField) || handleSecretCode(context, dialString) //for the form of *#*#<code>#*#*. /// @} /// M: for plug-in @{ || ExtensionManager.getInstance().getDialPadExtension().handleChars(context, dialString) /// @} ) { return true; } return false; }5.接下来分开两种讲，一种是直接弹出对话框的那种，类如*#06#，另一种则是调起别的应用等方式。 5.1 ）*#*#<code>#*#* /** * Handles secret codes to launch arbitrary activities in the form of *#*#<code>#*#*. * If a secret code is encountered an Intent is started with the android_secret_code://<code> * URI. * * @param context the context to use * @param input the text to check for a secret code in * @return true if a secret code was encountered */ static boolean handleSecretCode(Context context, String input) { // Secret codes are in the form *#*#<code>#*#* /// M: for plug-in @{ input = ExtensionManager.getInstance().getDialPadExtension().handleSecretCode(input); /// @} int len = input.length(); if (len > 8 && input.startsWith("*#*#") && input.endsWith("#*#*")) { final Intent intent = new Intent(SECRET_CODE_ACTION, Uri.parse("android_secret_code://" + input.substring(4, len - 4)));///android_secret_code://287 context.sendBroadcast(intent); return true; } return false; }有以上代码可知，最终是通过broadcast发送出去的，并往intent里面加载了2种数据：Uri和Action。Action：
private static final String SECRET_CODE_ACTION = "android.provider.Telephony.SECRET_CODE"; 接受端的注册方式，Action 和 data必须和发送的broadcast相匹配才行：/vendor/mediatek/proprietary/packages/apps/EngineerMode/AndroidManifest.xml
<receiver android:name=".EngineerModeReceiver" android:exported="true" > <intent-filter> <action android:name="android.provider.Telephony.SECRET_CODE" /> <data android:host="3646633" android:scheme="android_secret_code" /> </intent-filter> </receiver> /vendor/mediatek/proprietary/packages/apps/EngineerMode/src/com/mediatek/engineermode/EngineerModeReceiver.java
由上面代码可知，这就对应上了，在Receiver接受到广播后，启动对应的应用/Activity来处理接下来的工作。
5.2 ）*#06# 直接在Context中弹出对话框,显示IMEI信息
/packages/apps/Dialer/src/com/android/dialer/SpecialCharSequenceMgr.java
// TODO: Use TelephonyCapabilities.getDeviceIdLabel() to get the device id label instead of a // hard-coded string. static boolean handleDeviceIdDisplay(Context context, String input) { TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); if (telephonyManager != null && input.equals(MMI_IMEI_DISPLAY)) { int labelResId = (telephonyManager.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) ? R.string.imei : R.string.meid; List<String> deviceIds = new ArrayList<String>(); if (TelephonyManagerCompat.getPhoneCount(telephonyManager) > 1 && CompatUtils.isMethodAvailable(TelephonyManagerCompat.TELEPHONY_MANAGER_CLASS, "getDeviceId", Integer.TYPE)) { for (int slot = 0; slot < telephonyManager.getPhoneCount(); slot++) { String deviceId = telephonyManager.getDeviceId(slot); if (!TextUtils.isEmpty(deviceId)) { deviceIds.add(deviceId); } } } else { deviceIds.add(telephonyManager.getDeviceId()); } AlertDialog alert = new AlertDialog.Builder(context) .setTitle(labelResId) .setItems(deviceIds.toArray(new String[deviceIds.size()]), null) .setPositiveButton(android.R.string.ok, null) .setCancelable(false) .show();///直接在Context中弹出对话框,显示IMEI信息 return true; } return false; } *#07# 直接通过隐式intent启动相关应用 private static boolean handleRegulatoryInfoDisplay(Context context, String input) { if (input.equals(MMI_REGULATORY_INFO_DISPLAY)) { Log.d(TAG, "handleRegulatoryInfoDisplay() sending intent to settings app"); Intent showRegInfoIntent = new Intent(Settings.ACTION_SHOW_REGULATORY_INFO); try { context.startActivity(showRegInfoIntent); } catch (ActivityNotFoundException e) { Log.e(TAG, "startActivity() failed: " + e); } return true; } return false; } 以上就是Android通过Dialer方式启动暗码的大致源码流程分析。
